Eosinophilia with abdominal symptoms

General

Occurrence of abdominal complaints together with peripheral hypereosinophilia with or without increased IgE values and/or Charcot-Leydig crystals in the faeces is a frequent problem after travel in the (sub)tropics. A problem that occurs during or after a trip does not necessarily need to have a causal connection with that trip. It may be an incidental combination of eosinophilia and abdominal discomfort (no causal relationship). It occasionally is a cosmopolitan condition, though there is often an exotic cause.

Worm infestations are often responable for eosinophilia and abdominal complains. As a rule it can be stated that protozoa do not cause eosinophilia, with the exception of Sarcocystis (eosinophilic enteritis) and Isospora belli, although this is controversial.

Diagnosis

An attempt should be made to identify the parasite. This can sometimes be done via simple examination of the faeces. Concentration methods may be necessary, particularly with species that produce few eggs or larvae. X-rays, ultrasound, endoscopy and biopsies may have to be called upon for other parasites. Diagnosis can sometimes be made only on a surgical excision biopsy.

Faecal examination

• Ascaris lumbricoides can usually be detected easily by simple faecal examination. It should be pointed out that eosinophilia will occur principally during the parasite’s migration phase. Once the worm has grown into the adult animal in the lumen of the intestine the eosinophilia usually diminishes or returns to normal.

• Hookworms or ancylostomiasis can usually be found in the faeces without problems. If the ova have all eclosed it should be possible to differentiate the larvae from those of Strongyloides stercoralis. Oesophagostomum larvae resemble hookworm larvae.

• Schistosomiasis due to both Schistosoma mansoni and S. japonicum and to a lesser extent to S. intercalatum and S. mekongi is a major cause of eosinophilia and abdominal discomfort. One must not forget the acute Katayama syndrome, where initially no ova are found in the faeces.

• Strongyloides stercoralis larvae are often difficult to detect with a standard coprological examination, and therefore a Baerman concentration test can be indicated.

• It is most important to detect Capillaria philippinenesis as this parasite can have a fatal outcome. Severe abdominal pain, diarrhoea, emaciation and eosinophilia are the most obvious symptoms.

• Infestations by liver flukes such as Fasciola hepatica cause abdominal discomfort. After the parasite’s migration phase this is restricted to the liver.

• Infestations with intestinal flukes such as Heterophyes heterophyes, Metagonimus yokogawai, Gastrodiscoides hominis, Echinostoma sp, Euparyphium sp. and Fasciolopsis buski are usually asymptomatic, unless they are present in massive numbers. Metorchis conjunctus is a North American liver fluke that can cause acute abdominal pain and eosinophilia (e.g. after the human host has eaten raw fish).

• In rare cases it is adult tapeworms (Taenia sp., Diphyllobothrium latum, Hymenolepis sp., Dipylidium caninum, Inermicapsifer, Bertiella sp., Raillietina sp, Diplogonoporus sp.) which are responsible for abdominal discomfort.

  
  

Serology

Cross-reactivity is a problem with a number of serological tests for detection of worm infections. Serological testing can lead to suspicion of a visceral migrating larva (toxocariasis). Confirmatory diagnosis can only be made via biopsy. Detecting seroconversion is very important in Katayama syndrome. Initially negative while the patient has fever or thoracic and abdominal discomfort, this will later become positive. Ova of the schistosomes can subsequently be demonstrated in a rectum biopsy or urine sample (e.g. after swimming in Lake Malawi or in visitors of the Dogon plateau).

X-rays

Pentastomiasis (Armillifer armillatus infestation) is a rare cause of abdominal discomfort. Some time afterwards the calcified, comma-shaped larvae can be observed on an X-ray of the abdomen. If there is an infestation with exclusively male Ascaris lumbricoides, there will be no eggs in the stools, but the adult parasite can be detected via X-rays of the small intestine (barium transit). Calcified Echinococcus lesions are likewise detectable by X-ray.

Ultrasound

Liver flukes in the bile ducts or an aberrant migration of an adult Ascaris (Wirsung duct, choledocus) can be detected by ultrasound. An ultrasound of the abdomen can show dilated bile ducts. Liver lesions due to Capillaria hepatica are found only very rarely. No ova of this latter parasite appear in the faeces. Echinococcosis also tends to affects the liver. Fibrosis of the liver due to schistosomiasis can be suspected on ultrasound (periportal fibrosis).

Endoscopy

Anisakis worms (anisakiasis) can be diagnosed via gastroscopy and treated by mechanical extraction of the worm.

Biopsy and surgery

Rectum biopsy is a sensitive technique for detection of dead or living Schistosoma ova. Oesophagostoma worms can be found via surgery in intestinal abscesses. A few other rare parasites can also produce eosinophilic intestinal abscesses, namely: Angiostrongylus costaricensis, anisakiasis due to Anisakis simplex, Pseudoterranova decipiens, Phocanema, Contracaecum or Hysterothylacium. Eustrongylides sp. are large, bright red nematodes that elicit severe intestinal lesions. Macracanthorhynchus hirudinaceus is a thornhead worm or acanthocephalus that fortunately only seldom infects humans.

Category: Medicine Notes